The effects of ultrasonic frequency pulsed arc on wire + arc additively manufactured high strength aluminum alloys

Ultrasonic frequency pulsed variable polarity TIG and conventional variable polarity TIG arc heat source were employed to fabricate WAAM 2024 aluminum alloy thin-wall structures. Heat treatment procedure was conducted to process the components. The microstructure, porosity and mechanical properties were comparatively investigated to reveal the effects of ultrasonic frequency pulsed arc on the properties of WAAM aluminum alloys. With ultrasonic frequency pulsed arc, the grain was refined, and the porosity was significantly reduced. The micro hardness and its uniformity increased. Ultrasonic frequency pulsed arc can particularly increase the vertical tensile properties of heat-treated components and improve property isotropy. The refined grains and lower porosity in WAAM aluminum alloy structure with ultrasonic frequency pulsed arc were the reasons for property and isotropy improvement.